well, this is my second post on this pose, and again I had to post a picture from internet, but below I had the most similar pose in my archive. so accept my apologize!
If you have difficulties in poses which standing on one leg, try to stare to a point, not so far, not so close. slowly try to change the point, then gesture of your face (smile for example) and lately try to close your eyes.
and always... breathe!